Drive and registry control for rotary printing press

ABSTRACT

In a printing machine having a central roller, a printing roller provided with a shaft and cooperating with the central roller, and an inking roller cooperating with the printing roller, the invention provides a gear having a diameter corresponding to that of the central roller and being mounted for rotation with the same. Another gear is mounted for rotation with the inking roller in order to impart rotation to the latter, and a third gear is freely turnably mounted on the shaft of the printing roller and meshes with the other two gears to transmit motion to the gear which drives the inking roller. The third gear has a diameter corresponding to that of the printing roller. A differential unit is provided, having an input gear train that is driven by the third gear and an output gear train which is coupled with the shaft of the printing roller.

States Patent [191 Schirrich et a1.

DRIVE AND REGISTRY CONTROL FOR ROTARY PRINTING PRESS Inventors: Klaus Schirrich, Bielefeld-Brake;

Amir Erk, Bielefeld-Grossdornberg; Ottomar Tessmann, Jollenbeck, all of Germany Fischer & Krecke KG, Bielefeld, Germany Filed: Mar. 7, 1974 App]. No.: 448,576

Assignee:

Foreign Application Priority Data Mar. 12, 1973 Germany 2312175 U.S. Cl. 101/248, 101/352 Int. Cl B4lf 13/12 Field of Search 101/248,178, 181, 180,

References Cited UNITED STATES PATENTS 10/1938 Hoyt 101/178 1/1959 Bohme Frostad 101/248 [451 Feb. 4,1975

3,163,109 12/1964 Ste11ing,Jr. 101/248 X FORElGN PATENTS OR APPLICATIONS 1,056,573 3/1959 Germany 101/248 Primary Examiner-J. Reed Fisher Attorney, Agent, or Firm-Michael S. Striker [57] ABSTRAT In a printing machine having a central roller, a printing roller provided with a shaft and cooperating with the central roller, and an inking roller cooperating with the printing roller, the invention provides a gear having a diameter corresponding to that of the central roller and being mounted for rotation with the same. Another gear is mounted for rotation with the inking roller in order to impart rotation to the latter, and a third gear is freely turnably mounted on the shaft of the printing roller and meshes with'the other two gears to transmit motion to the gear which drives the inking roller. The third gear has a diameter corresponding to that of the printing roller. A differential unit is provided, having an input gear train that is driven by the third gear and an output gear train which is coupled with the shaft of the printing roller.

5 Claims, 2 Drawing lFigures PATENTEB 4W5 3.868 .5636

saw 2 or 2 DRIVE AND REGISTRY CONTROL FOR ROTARY PRINTING PRESS BACKGROUND OF THE INVENTION The present invention relates generally to printing machines, and more particularly to printing machines having printing rollers and inking rollers.

Printing machines of the type outlined above must be capable of being adjusted to different formats. This is done by replacing the printing roller when the format is changed, and usually also the inking roller. For adjusting purposes of this type, and also to provide adjustments for registry purposes and others, the known printing machines use a differential drive which is connected with an adjusting motor. A relatively small central gear drives an input gear of the differential drive, and the output gear of the differential drive is connected with an intermediate gear which serves to change the direction of rotation and which, in turn, cooperates with the so-called format gear mounted on the shaft of the printing roller. The format gear drives the gear which is associated with the inking roller so as to drive the latter.

This type of prior-art construction has a number of significant disadvantages. One of these is the fact that the entire power input required for driving the inking roller -which power input is very high by comparison to the power input of the printing roller and which varies very greatly unlike the quite constant power input requirement for the printing rollermust be supplied via the entire gear mechanism, including the differential unit. Evidently, this differential unit which inherently serves only for purposes of fine adjustment, must be made expressively large'for this reason. Moreover, the relatively great number of transmissions between the various gears tend to step up and magnify any flaws inherent in the arrangement, for instance manufacturing tolerance variations and the like, so that the overall operation of a printing machine utilizing this type of construction is relatively imprecise. The problem is further aggravated by the fact that the drive input for the inking roller, whose power requirements vary in any case, is supplied via this gearing.

An additional disadvantage of the prior art results from the fact that when adjustments have to be made,

for instance when a printing roller of a certain size has to be replaced with a printing roller of a different size because a different printing format is about to be run on the machine, substantial amounts of work in terms of adjustments, dismounting and remounting of components must be carried out.

SUMMARY OF THE INVENTION Accordingly, it is a general object of the invention to overcome the disadvantages of the prior art.

More particularly, it is an object of the invention to provide an improved printing machine of the type outlined. above, which is not possessed of the aforementioned disadvantages.

An additional object of the invention is to provide such an improved printing machine which is significantly simpler in its construction than what is known from the art, and which is highly reliable.

In keeping with the above objects. and with others which will become apparent hereafter, one feature of the invention recites, in a printing machine having a central roller, a printing roller provided with a shaft and cooperating with the central roller, and an inking roller cooperating with theprinting roller, in a combination which comprises a first gear having a diameter corresponding to that of the central roller and mounted for rotation with the same. A second gear is mounted for rotation with the inking roller to rotate the same. A third gear meshes with the first and second gears to transmit motion to the latter one, this third gear having a diameter corresponding to that of the printing roller and being mounted on and freely turnable about the shaft thereof. A differential unit is provided, having an input gear train driven by the third gear, and an output gear train which is coupled with the shaft of the printing roller.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a partly elevational, partly sectioned fragmentary view illustrating those portions of a printing machine which incorporate the present invention; and

FIG. 2 is a strongly diagrammatic fragmentary end view of the embodiment in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before proceeding to a detailed description of the invention as shown in FIGS. 1 and 2, it is emphasized that no attempt has been made to show a printing machine in specific detail. Only those elements which are necessary for an understanding of the invention have been illustrated; printing machines per se, in which the invention can be utilized, are well known to those skilled in the art. Reference may be had, for example, to US. Pat. No. 3,791,294 for structural details of a type of printing machine with which the present invention might be used. The disclosure of that patent is incorporated herein by reference for purposes of providing background information.

Turning now to FIGS. 1 and 2, it will be seen that reference numeral 1 identifies a central shaft which is driven in suitable manner and on which there is mounted a central roller 2 which rotates with the shaft 1. A printing roller 4 is mounted on a shaft 3 with which it rotates, cooperates with the central roller 2 in the usual manner. The printing roller 4 receives ink from an inking roller 6 which is mounted for rotation on a shaft 5 and which, in turn, receives ink from an ink pickup roller 7 which dips incrementally into an ink supply 8.

A first gear 9 is mounted on the central shaft 1 for rotation with the same; it has a diameter corresponding to the diameter of the central roller 2. The gear is in direct mesh with the teeth of a gear 10 whose diameter corresponds to that of the printing roller 4 and which is turnable about and with reference to the shaft 3, in a manner to be described subsequently. Also in direct mesh with the gear 10 is a gear II which is mounted on the shaft 5 so as to rotate the same when it is driven by the gear It). It is evident that for the transmission of motion from the gear 9 to the gear 11, the gear 10 constitutes only an intermediate gear.

A differential drive unit 12 is provided which can be operated by a diagrammatically illustrated adjusting motor 16. The unit 12 cooperates with an input gear train, the first gear 13 of which is also turnably mounted on the shaft 3 and has an axially extending hub on which the gear 10 is mounted. The gear 10 can be readily removed from the hub of the gear 13, but while it is in place on the hub it cannot rotate with reference to the gear 13. The latter, in turn, meshes with the teeth of a gear 14 that is mounted on an input shaft 15 of the differential gear unit 12. The unit 12 also has an output gear train including an output gear 17 which is mounted on the output shaft of the unit 12, which output shaft will be seen to surround a portion of the input shaft 15 with clearance. The gear 17 meshes with the teeth of a gear 18 which also has an axially extending hub and surrounds the shaft 3. In fact, the gear 13 is mounted on the hub of the gear 18. The gear 18 is fixedly connected with the shaft 3 to rotate the same. A slip coupling 19 of conventional construction is arranged between the first gear 13 of the input gear train and the last gear 18 of the output gear train. The arrangement is such that there is a transmission ratio of 1:1 between the gears 13 and 18.

When the slip coupling 19 is in engagement, the gears 10, 13 and 18 in effect operate as a single unit so that when the motor 16 is not operated for adjustment purposes, the transmission of motion takes place directly from the gear 9 via the gears 10, 13 and 18 to the shaft 3 of the printing roller 4. The other gears, including those of the differential gear unit 12, just rotate under no-load conditions.

Assuming the entire drive power requirement of the arrangement to be 100%, then in accordance with well established figures known to everybody having skill in the art, approximately 90% of this power requirement is needed by the inking roller 6 and the pickup roller 7. This means that only a residue of approximately 10% is required for the printing roller 4, and the present invention makes it possible to so adjust the slip coupling 19 as to take this into account, especially as the power requirement of the printing roller 4 is substantially constant. The gear trains which constitute the input and output gear trains for the unit 12, and the unit 12 itself, can be so constructed as to transmit approximately 1 of the total power requirement, rather than having to be constructed to be able to withstand 100% of the power requirement.

In operation, turning on ofthe motor 16 operates the differential unit 12 and an adjustment of the printing cylinder 4 thus takes place, with the clutch 19 slipping.

The size of the gear 9 and of the gears and 11, and their particular cooperation with the other gears of the input and output gear trains, provide for a particularly precise transmission of power, since as far as the substantial power requirements of the rollers 6 and 7 are concerned, the gear 10 now need only act as an intermediary between the gears 9 and 11 so that, in effect, the power can be transmitted almost directly from the gear 9 to the gear 11, eliminating the flow of power through the differential 12 and the associated input and output gear trains. The latter, in turn, can be made relatively weak since they need be able to transmit only approximately of the total power requirement, but at the same time as they are constructed more weakly than was heretofore possible, they can also be produced to much more precise tolerances. The overall effect of the invention is that the novel arrangement can be produced much more economically than anything that was known heretofore, and will operate with considerably greater precision than the prior art, particularly the very fine adjustments which are required for the printing roller 4.

The provision of the slip coupling or clutch 19 assures that in a very simple manner there is in effect a direct power transmission since, when the coupling engages, power is transmitted directly from the gear 9 via the gear 10 to the gear 13, and from there via the differential 12 directly to the terminal gear 18 of the output gear train. From there, in turn, power is transmitted directly to the shaft 3.

In actual practice this means that there is, in effect, only a single transmission in the drive system between the gear 9 and the printing cylinder 4, namely the one that is required between the gear 9 and the gear 10. All other connections are, in effect, fixed connections which contributes to the exceptional precise drive of the printing roller 4. The invention, of course, eliminates the purely power drive from the so-called precision drive, that is the major portion of the power which must be channeled to the rollers 6, 7 is separated from the smaller portion of the power that is required to carry out the various adjustments. Because of this, the slip coupling 19 need be constructed to operate only with respect to that amount of the power which is normally required by the printing roller 4, for instance 10% of the total, and which usually is constant or almost constant. It follows from this that the differential unit 12, also, need only be so constructed that when the motor 16 is turned on it can just overcome the retentive force of the slip coupling 19, so that adjustments can be carried out during normal operation of the machine and with the coupling 19 slipping.

FIG. 2 shows that the unit 12 and its input and output gear trains are mounted on a carriage 20 in which the printing roller 4 and its shaft 3 are also mounted. This means that when a change in format takes place, which requires a change in the cylinder 4 and the gear 10, it is a simple matter to cause the carriage 20 to be adjusted by movement along the machine frame 21, thus permitting free access to the roller 4 and the gear 10 which can be exchanged for a larger or smaller one, as the situation requires, whereupon the machine will rapidly be back in operative condition since all other gears which were mentioned above are in permanent mesh with one another.

By comparison to the prior-art adjustments of this type, this arrangement according to the present invention is superbly simple and permits very ready and speedy exchange of the printing roller 4 and the gear 10 for different ones. Readjustments are almost completely avoided when the exchange of the printing roller 4 and the gear 10 has taken place, because it is now merely necessary to move the carriage 20 until the new printing roller 4 is in engagement with the surface of the roller 2.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the type described above.

While the invention has been illustrated and described as embodied in a printing machine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can be applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. In a printing machine having a central roller, a printing roller provided with a shaft and cooperating with said central roller, and an inking roller cooperating with said printing roller, a combination comprising a first gear having a diameter corresponding to that of said central roller and mounted for rotation with the same; a second gear mounted for rotation with said inking roller to rotate the same; a third gear meshing with said first and second gears to transmit motion to the latter one, said third gear having a diameter corresponding to that of said printing roller and being mounted on and freely turnable about said shaft; and a differential unit having an input gear train driven by said third gear. and an output gear train coupled with said shaft of said printing roller.

2. A combination as defined in claim 1, wherein said input gear train has an initial gear and said output gear train has a terminal gear; and further comprising a slip coupling between and cooperating with said initial and terminal gears.

3. A combination as defined in claim 1, wherein said input gear train has an initial gear and said output gear train has a terminal gear; and further comprising an adjustable slip coupling between and cooperating with said initial and terminal gears.

4. A combination as defined in claim 1; and further comprising a motor operatively connected to said differential unit for operating the same.

5. A combination as defined in claim 1; further comprising a shiftable carriage which is movable with reference to said central roller transversely of the axis of rotation of the same; and wherein said printing roller and said differential unit together with said gear trains are mounted on and movable with said carriage. 

1. In a printing machine having a central roller, a printing roller provided with a shaft and cooPerating with said central roller, and an inking roller cooperating with said printing roller, a combination comprising a first gear having a diameter corresponding to that of said central roller and mounted for rotation with the same; a second gear mounted for rotation with said inking roller to rotate the same; a third gear meshing with said first and second gears to transmit motion to the latter one, said third gear having a diameter corresponding to that of said printing roller and being mounted on and freely turnable about said shaft; and a differential unit having an input gear train driven by said third gear, and an output gear train coupled with said shaft of said printing roller.
 2. A combination as defined in claim 1, wherein said input gear train has an initial gear and said output gear train has a terminal gear; and further comprising a slip coupling between and cooperating with said initial and terminal gears.
 3. A combination as defined in claim 1, wherein said input gear train has an initial gear and said output gear train has a terminal gear; and further comprising an adjustable slip coupling between and cooperating with said initial and terminal gears.
 4. A combination as defined in claim 1; and further comprising a motor operatively connected to said differential unit for operating the same.
 5. A combination as defined in claim 1; further comprising a shiftable carriage which is movable with reference to said central roller transversely of the axis of rotation of the same; and wherein said printing roller and said differential unit together with said gear trains are mounted on and movable with said carriage. 